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Re: Sauropod Necks



In a message dated 7/16/00 9:54:18 AM EST, sarima@friesen.net writes:

<< But even if so, the ancestors of sauropods must have been very *similar* 
to 
 prosauropods, in order to get from a _Herrerasaurus_-like condition to the 
 sauropod condition.  That is why I said "prosauropod-ish", not 
"prosauropod". >>

It more likely went from sauropod-ish to prosauropod-ish to herrerasaur-ish 
and, separately, to ornithischian-ish. Early sauropods retain all five 
functioning pedal digits, whereas in prosauropods the fifth digit is reduced, 
vestigial, or lost (only a splint metatarsal V remains). It is extremely 
unlikely that sauropods re-evolved a complete fifth pedal digit from the 
prosauropod or herrerasaur condition. The primitive dinosaur state is five 
functional pedal digits, from which the dinosaurs with reduced to missing 
pedal digits V must be descended.